Background

Following an anterior cruciate ligament (ACL) injury, the affected knee is known to experience bone loss and is at significant risk of becoming osteoporotic. Surgical reconstruction is performed to attempt to restore the function of the knee and theoretically restore this bone density loss. Cross-sectional analysis of the proximal tibia using peripheral quantitative computed tomography (pQCT) enables localised analysis of bone mineral density (BMD) changes. The aim of this study was to establish the pattern of bone density changes in the tibia pre- and post- ACL reconstruction using pQCT image analysis.

The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation.

Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry.

We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion.

Introduction Two commonly used labels for low back pain (LBP) are that of “mechanical” (1) or “inflammatory” (2). These labels have no universally accepted definitions. However, there are two distinct types of treatment for low back pain that seem to follow this definitional separation. That is, mechanical treatments (mobilisation, manipulation, traction and exercise) contrasted with anti-inflammatory treatments (medication and injections). The objective of this study was to obtain the opinion of five groups of experts about symptoms/ signs that may identify inflammatory and mechanical LBP.

Methods A convenience sample of 125 practitioners including spine surgeons, rheumatologists, musculoskeletal physicians, chiropractors and physiotherapists was asked to complete a questionnaire. Participants were asked to use a Likert (0–10) scale to indicate the strength of agreement or disagreement with respect to potential signs/symptoms identifying inflammatory or mechanical LBP. Ethics approval was obtained.

Results One hundred and five practitioners responded (81% response). No signs/symptoms were found to clearly distinguish between inflammatory and mechanical LBP. Nevertheless, seven signs/symptoms did show a higher score for either inflammatory or mechanical LBP, and a lower score for the other. Morning pain on waking, pain that wakes the person up, constant pain, and stiffness after resting (including sitting) were more likely to suggest inflammatory LBP, while intermittent pain during the day, pain when lifting and pain on repetitive bending were more likely to suggest mechanical LBP. There was however some disagreement between professions about the extent to which these signs/symptoms indicated mechanical or inflammatory LBP.

Discussion There was no clear agreement either within or between professions regarding the signs and symptoms that suggest mechanical or inflammatory low back pain. There was however weak agreement on seven signs/symptoms. Further research should be aimed at testing these for their ability to predict the outcome of mechanical and anti-inflammatory treatments of LBP.

We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts.

Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%.

There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce stress-shielding around the femoral implants. This leads us to question the use of more expensive cementless total knee components.

INTRODUCTION: Low back pain (LBP) is a common symptom in Australian adults. In any six months period approximately 10% of Australian adults suffer some significant disability from low back pain¹. One way of assessing the impact of LBP on a population is to estimate the economic costs associated with the disorder. This method is usually known as a “Cost-of-Illness” or an “Economic Burden” study². The economic burden of disease is often divided into direct and indirect costs and is most often calculated using the Human Capital Method2. According to this method the direct costs are represented by the dollar value of the interventions required for diagnosis, treatment and rehabilitation of the disease and the indirect costs by valuing the loss of productivity due to morbidity and mortality^2,3. We estimated the economic burden of LBP in Australian adults.

METHODS: Data sources used in this study were the 2001 Australian adult low back pain prevalence survey¹ and a multiplicity of Commonwealth, State and Private Health instrumentalities. Using the Human Capital Method direct costs were estimated on the basis of market prices (charges) and the indirect costs by valuing the loss of productivity due to morbidity. The conservative Friction Cost Method for calculating indirect costs was also used as a comparison⁴. A sensitivity analysis was undertaken where unit prices and volume for a range of services were varied over a feasible range (10%) to review the consequent change in overall costs.

RESULTS: We estimated the direct cost of low back pain in 2001 to be AUD$1.02 Billion. Approximately 71% of this amount is for treatment by chiropractors, general practitioners, massage therapists, physiotherapists and acupuncture. However, the direct costs are minor compared to the indirect costs of AUD$8.15 Billion giving a total cost of AUD$9.17 Billion. The sensitivity analysis showed very little change in results.

DISCUSSION: The economic burden of low back pain in Australian adults represents a massive health problem. This burden is so great that it has compelling and urgent ramifications for health policy, planning and research. This study identifies that research should concentrate on the reduction of indirect costs. This is not to suggest excluding direct cost research, as it is likely that early, efficient and evidence-based management of low back pain in the first instance may lessen the indirect costs that often follow. These startling results advocate urgent Government attention to LBP as a disorder.

INTRODUCTION: There is no shortage of treatments for low back pain (LBP), including medication, injections, bed rest, physiotherapy, chiropractic, osteopathy, acupuncture, massage therapy, and surgery. In addition to this are a plethora of home and folk remedies. However, there is still doubt about the efficacy or effectiveness of even the most common forms of therapy¹. Also, little is known about the proportion of persons who seek care for LBP, why they sought care, the type of care sought and indeed what differentiates them from those who do not seek care at all. The objective of this study was to determine the characteristics of Australian adults who seek care for LBP, including the type of care they choose and any factors associated with making those choices.

METHODS: An age, gender and State stratified random sample of 2768 Australian adults was selected from the Electoral Roll. This sample were mailed a fully structured questionnaire that included a series of questions relating to care-seeking for LBP, choice of provider and types of treatment received. In addition a series of questions were asked relating to demographic characteristics, socioeconomic variables, and severity of LBP. Also asked was cigarette smoking status, anthropometric variables, perceived cause of low back pain, emotional distress, job satisfaction, physical fitness, past five year health status, and whether the subject feared LBP could impair their work capacity or life in the future.

RESULTS: The survey response rate was 69.1%. The sample proved to be similar to the Australian adult population. The majority of respondents with LBP in the past six months did not seek care for it (55.5%). Factors that increased care seeking were higher grades of pain and disability, fear of the impact of pain on future work and life and female sex. Factors decreasing the likelihood for seeking care were identified as the cause of pain being an accident at home and also never being married. General medical practitioners and chiropractors are the most popular providers of care.

DISCUSSION: High levels of pain and disability equating with higher levels of care-seeking would not surprise, however fear as a motivator for care-seeking has implications for clinical practice. Another important issue is the type of care selected for LBP. Using the best evidence available for the management of LBP is now seen as a responsibility for all practitioners. It would be useful to compare care-seeking with the evidence of the efficacy and effectiveness of the various therapies utilised.

Introduction: Estimates of low back pain prevalence show that low back pain is a common problem particularly in western countries. But the extent to which low back pain causes true disability and not just nuisance pain casts doubt of the utility of these estimates. No studies have been performed in Australia to study both the prevalence and disability associated with low back pain in the population. Accordingly, the objectives of this study were to determine the prevalence ranges and retrospective one year incidence of low back pain together with any related disability in Australian adults.

Methods: A survey was mailed to a stratified random sample of 3000 Australian adults selected from the Electoral Roll. There was a 69% response rate. Demographic variables of respondents were compared with those of the Australian population taken from Census data. Selective response bias was investigated using wave analysis. A range of prevalence data were derived as was a disability score using the Chronic Pain Grade Questionnaire¹ (CPG). The CPG has demonstrated reliability and validity in measuring pain and disability in postal surveys². Prevalence and disability estimates were variously standardised using gender, age and marital status.

Results: There was little variation between the sample and the Australian adult population. There was no significant selective response bias found. The sample point prevalence was estimated at 25.5% (95% CI, 23.6–27.5), six-months prevalence was 64.6% (95% CI, 62.6–66.8) and lifetime prevalence was 79.2%, (95% CI, 77.3–80.9). The retrospective one year incidence was 8.0% (95% CI, 6.9–9.3). In the previous six months period 42.6% (95% CI, 40.4–44.8) of the adult population had experienced low intensity pain and low disability from it. Another 10.9% (95% CI, 9.6–12.3) had experienced high intensity pain, but still low disability from this pain. However, 10.5% (95% CI, 9.2–11.9) had experienced high disability low back pain. The mean time-off from usual activities in the past six months for this group was 1.6 months (95% CI, 1.3–1.9), the median was 18 days. There was no gender difference for a high disability rating or time-off.

Conclusion: Low back pain is a very common problem in the Australian adult population, yet most of this is low intensity and low disability pain. Nevertheless, over 10% had been disabled by low back pain in the past six months and it required significant time off from usual activities.